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Worker Health Study Summaries

Research on long-term exposure

Industrial Sand Workers (Silica Exposure) (2)

NOTE: This page is archived for historical purposes and is no longer being maintained or updated.
NOTICE: These are NIOSH
Archive Documents, and may not represent current NIOSH Policy.
They are presented here as historical content, for research
and review purposes only. This collection of Worker Notification
Materials and any recommendations made herein are relevant
for specific worker populations. The results do not predict
risk for a given individual. The results may not be universally
applicable.

2002

Study Background

On January 18, 2002, NIOSH sent the results of a study of industrial
and workers from 18 different plants to each participant in the study.
The study focused on the health effects of exposure to silica.

Who was included in the NIOSH study?

NIOSH based their results on the personnel records of these 4,626
former and current industrial sand workers. The records were
collected during 1987-1988.

How did NIOSH do the study?

We estimated silica exposure for each worker by using available
silica exposure information based on each worker's job and
plant.

We collected smoking information for about 10% of the workers.
We used the information to represent the smoking histories
of the whole study group.

We collected death certificates for the workers who had died.

We compared the number of deaths from each cause among the
workers, to the number of deaths expected in the U. S. general
population who were of similar age, race, and sex.

We compared the number of workers who had end-stage kidney
disease with the number of people expected based on
the U.S. general population. (We did not compare the number
of deaths.)

We also tested to see if the number of deaths from each cause
and the number of cases of end-stage kidney disease were
increased among industrial sand workers who had greater
exposure to silica as compared to those who had less exposure.

What were the study results?

We found that a statistically significantly greater
number of deaths occurred from the following causes among
industrial sand workers compared to what was expected, based
on the U.S. general population. This means that the larger
number of deaths from these causes among the sand workers
was very unlikely to have occurred by chance.

Lung Cancer

If the risk in industrial sand workers was
the same as the risk in the general public, we would have
expected 68 deaths from lung cancer. Instead we found 109.
This was approximately 1½ times the number of lung
cancer deaths expected. Excess risk of lung cancer has also
been found in other studies of silica-exposed workers.

The greater the total amount of exposure to silica, the greater
was the risk of lung cancer in industrial sand workers.

Pneumoconioses/Silicosis

Pneumoconioses are very rare causes of death due to breathing
in dusts. Silicosis is one type of pneumoconiosis caused
by breathing in silica dust. Silicosis causes scarring of
the lungs and severe breathing problems.

Among this population, the pneumoconioses deaths were all likely
due to silicosis because of the workers' exposure to silica
dust. If the risk in industrial sand workers was the same
as the risk in the general public, we would have expected
less than 1 death from all pneumoconioses, but we found
17.This number was more than 17 times the number expected.
Excess risk of pneumoconioses has also been found in other
studies of silica-exposed workers.

Tuberculosis (TB)

If the risk in industrial sand workers was the same as the
risk in the general public, we would have
expected 1½ deaths from TB, but found 5. This number
was more than 3 times the number expected. Excess risk of
TB has also been found in other studies of silica-exposed
workers.

End-Stage Kidney Disease

If the risk in industrial
sand workers was the same as the risk in the general public, we would
have expected 12 cases (not deaths) from end-stage kidney
disease, but found 23. This number was nearly 2 times the
number of cases expected. Excess risk of end-stage kidney
disease also has been found in other studies of silica-exposed
workers.

Healthy kidneys remove waste materials from blood. End-stage kidney
disease is the most serious form of kidney disease, when
the kidneys no longer work. To live without kidney function,
people need dialysis or a kidney transplant. Milder kidney
disease can be treated to prevent end-stage kidney disease.

Arthritis

If the risk in industrial sand workers was the same as
the risk in the general public, we would have expected less than 5 deaths
from arthritis but found 23. This number was more than 4 times the number
expected. Excess risk of arthritis has been found in some other studies
of silica-exposed workers.

Heart Disease

If the risk in industrial sand workers
was the same as the risk in the general public, we would
have expected 270 deaths from heart disease but found 330.
This number was nearly 1¼ times the number of heart
disease deaths expected. Respiratory diseases such as silicosis
and lifestyle factors such as smoking might account for
some of the increased risk for heart disease. However, without
more information on lifestyle factors within this cohort,
we cannot say for certain why deaths from heart disease
were increased.

Protect Yourself from Lung Disease

Smoking

Smoking greatly increases the risk of lung cancer and lung diseases,
as well as many other diseases. If you smoke, you should
quit. Even if you have smoked for many years, stopping now
will improve your health.

Avoid secondhand smoke, dust, and other air pollutants, whenever possible.

Symptoms

You should see your doctor if you have the following symptoms:

periodic respiratory infections

a continuous cough

trouble breathing

feeling unusually tired

Your doctor may do a physical examination that includes a chest
x-ray and a pulmonary function test (PFT).

Flu Virus

See your doctor each year for a flu shot. The flu virus is constantly
changing, so new vaccines are developed yearly to protect the public
from the most recent strains of flu. For greatest protection, the best
time to get the flu shot is between early October and mid-November.

Persons 65 years of age and older should get the pneumococcal vaccine.
This shot helps protect against the most common type of
bacterial pneumonia. Both the flu and pneumonia shots can
be given at the same time. Unlike the yearly flu shot, you
need to get the pneumococcal vaccine only once in a lifetime.

Avoid exposure to colds and flu at home and in public.

Tuberculosis

Tuberculosis (often called TB) is an infectious disease that usually
attacks the lungs. Your doctor can give you a TB skin test
to find out if you have the TB infection.

Diet & Exercise

Follow a nutritious, well-balanced diet, and maintain your ideal
body weight. Eat lots of fresh fruits and vegetables. At
least 5 servings a day may help to prevent cancer and other
diseases.

Get regular exercise daily, without tiring yourself too much.

Protect Yourself from Kidney Disease

You should see your doctor if you have the following symptoms:

Swelling of parts of the body, especially around the eyes and ankles

Lower back pain, where the kidneys are located

Burning
sensation during urination

Bloody, foamy or coffee-colored urine

Changes in how often you need to urinate

Changes in urine color

Your doctor can decide what screening tests you may need if you have
any of these symptoms.

Where To Get Additional Information

For more information call NIOSH toll-free: 800-356-4674

For more information about lung cancer and
other lung diseases, call or visit these web sites: